Study On Earth Pressure Based On The Unified Strength Theory

The determination of forces on structures which are connected to earth mass is of paramount importance in applied Geotechnical Engineering. Classical soil pressure theories enunciated by Coulomb and Rankine have been widely used for the soil pressure analysis and the design of the retaining structures within the validity of the assumptions of these theories. The solutions based on the Mohr-Coulomb theory are not considering influence of the intermediate principal stress, but the unified strength theory by Yu-Maohong can solve the problem well. The unified strength theory is a new kind of strength theory to have unified mechanical model and theoretical assumption, and a simple, linear and unified mathematical expression adapted for many kinds of materials. The study on soil pressure based on the unified strength theory is rather little, so a series of new achievements in this aspect are acquired.The shear strength unified formula of the unified strength theory under the condition of plane strain is introduced into limit equilibrium, and then the formula of active earth pressure is deduced for the wall movement modes. The tradition formula is popularized by the unified strength theory. According to the theory of Prandle, the unified earth pressure formula of retaining wall with logistic spiral sliding surface is derived. The calculation of normal earth pressure is based on semi-infinite assumption , so the unified formula of finite soil pressure is obtained through the limit analysis of soil mass. In the earth pressure on retaining wall influenced by anisotropic damage, the unified equations are obtained and they are suitable for geomaterials.Pile row structure is one of the most common retaining structures for deep excavation. In the last, so the active earth pressure considering the intermediate principal stress is deduced through the three-dimensional failure of soil mass.